Looking good. I would like to build something like this in my shed with some T5's I have laying around to start seedlings and veg before moving plants to flower tent.
If the air in your grow room should be replaced every 5 minutes, would it be better to have the AC in the lung room?
Just asking, only a newbie here.
This is a sealed room with co2 injection.
If your running an exhausted room you dont need a lung room per se. The room that the tent or box sits in is the lung room and you cut exhaust and it intake holes as you would a tent.
The bonus to this over a tent in that case is you can make the dimensions you like and that generally means you can go taller or customize it to your exact needs.
The advantage to sealed is you have complete control over co2 and environment when using equipment and controllers. So you just enter the setpoints and they stay where you want no matter whats going on in the room that the grow box is in. Eg the garage in this case can get very hot or cold but it wont influence the conditions inside because its sealed. Also less risk of bugs, causing humidity damage to your property, faster growth rates etc but does cost a bit more to setup